import sys
import os
from pathlib import Path

# Add the project root to Python path if running as script
if __name__ == '__main__':
    project_root = Path(__file__).parent
    sys.path.insert(0, str(project_root))

from pr_review.config import PRAnalyzerFactory
from pr_review.github_client import GitHubClient


def create_pr_comment(
    github_client: GitHubClient, analysis: str, pr_number: int, environment: str
) -> None:
    """Create comment on PR or print in dev mode."""
    if environment == 'dev':
        print(analysis)
    else:
        github_client.collapse_previous_reviews(pr_number)
        github_client.create_comment(pr_number, analysis)


def main() -> None:
    """Main function to orchestrate PR review process."""
    # Get environment variables
    environment: str = os.environ.get('Environment', 'dev')
    gh_token: str = os.environ.get('GITHUB_TOKEN', '')
    pr_number: int = int(os.environ.get('GITHUB_PR_NUMBER', ''))
    repo_full_name = os.environ.get('GITHUB_REPO_NAME', 'theorchard/terraform-infra')
    try:
        repo_owner, repo_name = repo_full_name.split('/', 1)
    except ValueError as e:
        print(f"GITHUB_REPO_NAME must be in format 'owner/repo', got: {repo_full_name}")
        raise e
    timeout: int = int(os.environ.get('TIMEOUT', '600'))

    # Validate all required env vars are present
    if not all([gh_token, pr_number, repo_owner, repo_name]):
        print('Missing required environment variables. Please set:')
        print('GITHUB_TOKEN, GITHUB_PR_NUMBER, GITHUB_REPO_NAME')
        sys.exit(1)

    print(f'Starting PR review for PR {pr_number} in repo {repo_name}')

    try:
        # Create repo-specific analyzer
        analyzer = PRAnalyzerFactory.create_analyzer(repo_name, gh_token, repo_owner)

        # Skip draft PRs — Atlantis doesn't run on them, so analysis would always fail
        if analyzer.github_client.is_draft_pr(pr_number):
            print(f'PR #{pr_number} is a draft, skipping analysis.')
            sys.exit(0)

        # Analyze PR
        analysis = analyzer.analyze_pr(pr_number, timeout)

        # Post comment
        create_pr_comment(analyzer.github_client, analysis, pr_number, environment)
        print('Analysis posted as comment on PR')

    except ValueError as e:
        print(f'Configuration error: {e}')
        sys.exit(1)
    except TimeoutError as e:
        print(f'Timeout error: {e}')
        sys.exit(1)
    except Exception as e:
        print(f'Unexpected error: {e}')
        sys.exit(1)


if __name__ == '__main__':
    main()